Puncture-proof tube for pneumatic tires.



HTED STTES PATE??? @Fiiiiil TUBES NB ACCESSQRIES, LIMITED, A CORPORATION '3E CLAEA.

PUNCTUBE-PBOOF TUBE FOR PNEUIMATIG TIRES.

Application filed August 11, 15H3i ifi; @ZZ 'iff/wm t may concern.'

lie it line-wn that l, ALBERT Ennis HEX ourson'. -a subject of the King of Great Britain, and resident of the city of Toronto, bounty oi York, Province ot Ontario, in the Dominion of Canada, have invented certain ne*A f and useful iinproif'ements in Puncture- Proof Tubes for Pneumatic Tires, and do herebtY declare that the following is a full, clear, and exact description of the same, such as will enable others skilled in the art to which vit appertains to make and use the saine.

l a i aware that it not'neiv to the art to make an inner tube with a thickened tread portion and to produce coi'npression of the thickened portion by turning the tube inside out by either "pulling,y one end outwardly baal; upon the body of the tube or inwardly Within the body oi? the tube by use of special forceful means; but in so doing the material of the tube often strained so as to weaken and distort it in places. Besides, through the method ot joining; together the ends of the tube a pliable'portion of the tread is created at the point of juncture, thus de stroying the uniformity of the character of the said trend portion of the tube.

The objects of my invention are, first: to Aprovide an inner tube for pneumatic tires, haring a uniformly thickened tread portion, so constructed as to snugly it the casing when inflated, thus overcoming' the tendency to creep; second: to provide for the circum- `terential compression of the tread portion by reversing the tube without undue strain; third: to provide means for constructing` the tube so as to regulate as may be desired the amount ot' lateral compression ot the said thickened tread portion of the tube when completed; and fourth: to guard against the tendencj.T of the valve to tear out owing to the creeping of the tube in the casing.

In the drawings Figure l is a sectional view of the tube as it would appear upon the circular form. Fig. 2 shows a sectional view ot the tube removed from the form, reversed and joined together, and then inflated. Fig. A is an enlarged transverse sectional View of the portion of' the tube at the location where `the valve is inserted, showing the overlapping flanges and the embedded strengthening Jfabric. Figs. 3 and 4 show one tyoe form on which the tube is built Specification of Letters Patent.

Patented Mar. 721. 119 if.

serie no. 784,166.

up and vulcanized. Fig. 5 shows a sectional 5 rien' of a modified type of the circular forni for the tube. Fig, G is a sectional view oi another form which ma)v be used. Fig 'i' is a longitudinal sectional elevation of s tion oi the tube showing the Tposition oi" the fabric in the thickened tread portion as is built up on the form. Fig. 8 is au enn larged longitudinal sectional 'view of portion oi' the inner wall ot the tube 'iv the valve is inserted showing the strengt ening fabric.

Like numerals of reference indicate coi'- respondingA parts in each ligure.

l. is an air tube for pneumatic tires having; thickened tread portion graduallyY reducing in thickness as it extends laterally troni the center oi' the said tread dow the of the tube. ln Fig. l, the tube i ha the thickened tread portion .is shown i the circular forni 3 upon whicn it is b The material does not eoinpletelv surrf., the iorin transversely but tern'ii tes in reduced portions 4--l', which are ada te to overlap each other when the tube is reversed, shown in 2. The fabric 3 51e and 5 is embedded in the thickened treni Yportion at a. suitable distance from inner surface 6, and is applied in longitudirnil. sections leaving a space G betweenthe ends of the strips, and in suoli formation as to permit a certain amount ot longitudinal tension. After the first series of strips 5 -s applied, additional rubber is laid on and then a second series of strips 5 is applied covering the spaces in the series 5 and eas so tending' so as to overlap the ends of the sections oi the series 5, additional rubber is then added as may be desired. F ig. l shows sectional view throuoh a part of the tube in which only the series 5 is shown, being one@ 95 site the space in the series 5', while in Fi i' the double series is shown.

This method of construction, more particularlyY shi'iwn in Fig. 7, provides sutlicient amount of having a transverse joint, so that the tread will be uniform throughout, thus removing a anse of creeping which is found in the ordinary thiol-oued tread. lillhen the proper thickness of tread and Wall is obtained, the rubber is rolled and wrapped, and is then rulcainizedv upon the form to a suitable stage, after which it is easily removed from the form without undue strain owing to the elastic character of the thinner les of the tube. The tube is then easily reversed laterally or turned inside out shown in Fig. :2, after which the edges Ar-4f may he joined "then the a" valve seat being inserted durinil` thisl o; ation.

In lfif the thickened portion of the "i inside the fabric 5 will be in comn on lungitmiinallyv owing to the fact of the inversion of the tube and the restrain ing influence of the fabric 5 and 5V, While the joining together of the overlapping por tions 1i and fl' in conjunction with the inflation of the tube produces lateral compres sion of the thickened tread portion, the amount of said ,lateral compression being regulated by the ratio of the transverse seo tional diameter of the form 3 to the intended diameter of the finished tube, I.

When building up the tube on the form, a suitable strengthening fabric 7 and 7' is in laid at the location at which the air valve is to be inserted. This is shown in transverse section in Fig, 2^, and in longitudinal section in Fig. S. Owing to the presence of this fabric the ordinary valve cannot be inserted 0r removed in the usual Way at' this point, but may be applied in the usual way at any other suitable location. l therefore provide avalve seat 8 having a shank 9 provided with an aperture ll) and holes llv by means of which the valve Seat may be held from turning by a wrench. Said seat may readily be inserted from Within the tube when the parts' as shown in Fig. fl are brought together so that the holes l2 and l2 in the overlapping portions /t--lare in alinement. The shank extends through the material a suitable distance so as lto receive the washer 13 and the nut 11i. The shank 9 is interiorly screw-threaded to receive the stem 15 of' the ordinary valve which is threaded to engage the shank 9. The rubber washer 1G engaging the end of the valve stem 15 and the shoulder 17 of the valve seat 8' prevents any leakage of air. After the valve has been inserted the remainder of the over lapping portions 4rd may then be joined together. When the tube is thus completed it is partially' inllated and then further vulcanized, it is then ready for use.

Figs. 3, 4. and t3 give details of the forms on which the tube may be molded.

In Fig. T the relation of the fabric SM5 as it is embedded in the thielrened tread pon lion is :finire rlftai ltis understood that this --method of inserting the fabric may be used in and applied to all thickened treads for inner tubes, whether cons cted as described in the specification herein or on any circular or otherwiseshaped form where fabric is required for the purpose of compression.

.By constructing the tube as above described, l have provided for threefold compression of the thickened tread portion in such degree to render the saine proof against the results of puncture, while the thickened' tread being uniform throughout and provided with a certain amount of elasticity, will. lit snugly in the casing, and thus overcome the dilliculty caused by the creeping of the tube in the casing.

l have. thus provided a puncture proof inner tube for pneumatic tires having a uniform tread `which can readily be constructed, and from which has been eliminated the weakness inherent to the socallcd puncture proof tubes such as have been known to the art, and I construct the same in a manner which has not heretofore been patented or known before my invention thereof.

l do not confine myself to the exact forms or methods of construction shown in the drawings and described in the specification but may vary the saine without departing from the spirit of my invention.

.l claim:

l. A. tube for v,pneumatic tires having its tread portion held in compression by a series of unconnected terminally overlapping strips of substantially non-elastic llexible material embedded therein adjacent the ultimate tread surface. l

S2. tube for pneumatic tires having its tread portion held in compression by a serics'of unconnected fabric strips embedded therein adjacent to the ultimate tread surface, the adjacent ends of the strips being surrounded by and separated from each other by unrestricted rubber.

A tube for pneumatic tires having its tread portion held in compression by a series of unconnected terminally overlapping fabric strips embedded therein adjacent to the ultimate tread surface.

4. A tube for pneumatic tires having,r its tread portion held in compression by a series of unconnected terminally overlapping fabric strips embedded therein adjacent to the ultimate tread surface and spaced apart radially by intermediate rubber.

A tube for pneumatic tires having its tread portion held in compression by terminally concentric series of unconnected fabric elements embedded therein adjacent to the ultimate tread surface. y

6. A tube for pneumatic tires having its tread portion held in compression by terminally ermcentric series of unconnected fabric cleinents embedded therein adjacent to the niinnme rnml Snrfacfe, the fabric elcmcns :irrzingvfl in singffvrefl relation longiiniin'illj. nf the treuil.

inlii l'nr pnoinnntii: tirv having' irs nl [mriinn lielll in wnlprcshion by Q0nf'vnriff Arrive: nl: terminally Cnxnfnnlriff and nnrnnnwml nmrnlzistn Moment@ embedded ww-in mlimvnt to tlm iitinmte trend snrlrl' 'x niiifor pnmnnalic tires haring its iff gmrlinn llolil in voninvwion by z se m. .fwrininzallr uoincnu'xc und unconlnlirii nlA 'wnts mnlxwlilml therein ndi #lnt nlinn@ trie; l #nrznten the fleni" one series occupying a staggered :in with those of the other sericb- Vl. *i puncture proof tube for pneumatic 11n i ruilt nimn :i vii-cular forni, said tube l ina :i uniformly tliirlned trend portion nznli-rilntinl enlirety provided will: Mining @miti-:illy dispoScil fabric stripr .Iwillilwl mlinfent to tlm 'iiltinmln treuil nlm-v lll 'Fabric strips holding the tread ,wrxiiin in mnnn'cshinn.

l n :a 'lm'iffe nl lille nntnro lu-scribed. in wignfiiinnl'inn. n, rnlilmr mln lmrin; a tre-2id g Mimi. libriioinlieililml in lli@ linlie adapt 

